Hi GEM team,
Here is a message from Miles Silman and his team, who are getting ready for a big re-census in the Andes: "There is an assumption that I wanted to check on about the strapping-tape dendrometers. Has anyone ever checked for stretch? For example, putting one on a steel or concrete lamp post, etc.? If so, what did they find?"

Calling all GEM users:
I hope your year has started on a good note?
I would just like to let you know that the GEM website is likely to get a lot of hits in the next few weeks, as the first GEM Nature paper is coming out soon, with good press coverage (Congratulations, Doughty et al.!!!).
This is a good time to update your profiles, make sure you have a photo on your avatar, post latest pictures and comments: use the GEM website to promote yourself and your work! Please do not hesitate to contact me if you have any trouble logging in. Login is at the top right of your screen. Bonne chance, Cécile

We have just published in Ecosystems a description of the carbon cycle of the core 1 ha intensive plot in Wytham Woods.This is work emerging from the DPhil thesis of Katie Fenn. The work shows that the plot takes up 22 tonnes of carbon every year through photosynthesis, but less than 10% of this ends up as wood growth. Much more productivity ends up in the leaf canopy and even in fine roots. This is one of the few full descriptions anywhere of carbon cycling in mixed-age temperate broadleaf woodland (most work is on either plantations or coniferous forests), and forms part of our Global Ecosystems Monitoring network GEM. We also show how well our bottom-up carbon cycle measures track the eddy covariance measurements of total canopy CO2 exchange, giving increased confidence in both.

Congratulations to Katie for persisting with this! It is a wonderful contribution to both our global studies, and to the multi-discplinary and multi-faceted studies at Wytham Woods.

Dear Gem teams, the Environmental Change Institute are experimenting with live broadcast (and downloadable videos) of some of the MSc lectures on the theme "Welcome to the Anthropocene". Lectures will start next week. We encourage you to listen in and ask questions by twitter, and particularly encourage participation from tropical countries.

Congratulations to the GEM team (Chris, Yadvinder & Liana) who co-authored a paper in Nature this week (cover story):

"The paper answers a long-standing question about the net carbon balance of the Amazon forest. It uses aircraft flights throughout the year at four different locations to measure the change in carbon dioxide concentration if air as it passes over the Amazon Basin. The study shows that in wet years and wet seasons the Amazon is a net sink (i.e. absorbs carbon) from the atmosphere, but in dry years and dry seasons it is carbon neutral or a source of carbon. Our main contribution in Oxford was to provide insight from our RAINFOR-GEM intensive monitoring plots across Amazonia, which suggest that the loss of the carbon sink was caused by a reduction in photosynthesis." (Y. Malhi blog, Feb 2014)

Hi Guys, I have just been hitting my head against a brink wall trying to figure out he best way to export ggplot2 graphs in 600 dpi .tiff format for publication. This may be useful for many of you. The code is

We have a new paper our in the Journal of Geophysical Research - Biogeosciences, on the net primary productivity of an old growth dipterocarp forest at Lambir, Sarawak, Borneo. This emerges from the DPhil thesis of our former student Kho Lip Khoon. Up until now all our published studies on productivity have been from Amazonia. This is the first of a wave of results that will be emerging from our current work in Asia and Africa. More papers will also been emerging from Khoon's work in Lambir. Overall this work shows that productivity is higher on the clay soils of Lambir, but lower on the sandy soils, and on the clay soils is higher than observed in Amazonia.

We have a new paper in Oecologia from our Zambian former DPhil student Royd Vinya, emerging from his DPhil work on plant hydraulic traits in wetter and drier environments in the miombo woodlands of Zambia. The paper shows that tree species with a a narrow (wetter) habitat range were more vulnerable to hydraulic cavitation range than those adapted to drier sites, which had broader ranges. We observed a strong trade-off between vessel conductivity and resistance to cavitation, suggesting that tree hydraulic architecture is one of the decisive factors setting ecological boundaries for principal miombo species. While vessel diameters correlated weakly cavitation vulnerability, it was vessel length that was positively and most significantly correlated. This paper gives us insights into the role and flexibility of plant hydraulic architecture in determining species' ecological ranges.

We are advertising a position for a four-year postdoc to work on carbon plots and plant traits in the Amazon and Atlantic forests, as part of the new NERC project ECOFOR. The post would be 50% Oxford, 50% Lancaster. It would be based in Lancaster for the first two years, with extensive periods in Brazil getting the field operation going, and then would be based in Oxford for the second half with a focus on data analysis, databasing and writing up.
Job details at:https://hr-jobs.lancs.ac.uk/Vacancy.aspx?ref=A813
Closing date Wed 13th November 2013.
Feel free to contact me for any informal enquiries

Hope things are going well. I am quite enjoying being back in Borneo. One of the main tasks this trip is finally to start taking hemispherical photos. However, as I have never done it before, I would appreciate some advice from more experienced people.

Firstly, I am not quite sure how to set up the photo points in my very shrubby logged plots. The Rainfor-GEM manual states that “At each subplot, locate an area close to the centre that is free of vines or branches at least 2 m above the camera lens (which should always be 1 m from the ground)” (page 72), but this is proving quite challenging in the logged plots. What do you think, is it more important to have the photos taken in representative spots, which match what the litter traps are collecting, or is it more important to enforce this 2 metre rule? We can find spots that don’t have anything directly above the camera lens, but I am not sure how large a buffer area is needed around the lens.

Secondly, how bright should the photos be for analysis? If I don’t adjust the brightness, they look fairy dark, but the contrast between vegetation and sky is good. I am taking three photos at each point, each at slightly different brightness, the medium setting being 0, but even the brightest setting I am using at the moment is quite dark. This is easy to change, but I’m not sure what kind of images work best in the analysis stage.

Any other tips also very welcome, if you can think of something I should know.

Hello,
I have tested the CI-110 Digital Plant Canopy Imager, and although the equipment is not very robust, you get measurements instantaneously (LAI, PAR, etc). It has the same issues I have observed when processing the hemi-photos (one gets mostly plant area index rather the LAI as the separation between branches and leaves are tricky. Pros is little time for processing data, Cons is that using a tablet in rainforests (hot and wet) may push the equipment a bit too much (our is being fixed now).
Good luck Terhi!
Liana

One thing to consider is how to incorporate understorey LAI. Perhaps you could keep the understorey you clear around each hemiphoto point and either (1) scan all the leaves to calculate their area or (2) weigh them then apply an SLA estimate to get their area. If you know the ground area cleared this will provide direct estimates of understorey LAI.

Sorry I missed you! We had what sounds like a fairly similar problem in our 10 year post-logged plot in Ghana. Hard to say without seeing your plot, but in Ghana, we had no choice but to clear at least 1 m in all directions upwards of the lens because what we were taking as a photo was clearly just not representable of the true canopy (pretty much black photo with 100% ‘canopy cover’). As for being in the centre of the subplots, close to the littertraps, sometimes it is not possible to be within a couple of meters, so just as close as possible. As for exposure, I also got the guys started by taking 3 a different light levels and without having done much CanEye analysis yet, my feeling is that the darker photos are the better ones, because the contrast between the vegetation and the sky is much greater/clearer and therefore more representative of the true canopy cover again.

Another couple of things to remember are to take the photo in the same direction every month (i.e. always North) and make sure the lens is pointing directly upwards – I find placing a spirit level on the lens cap is easiest to do achieve this, before removing the cap and taking the photo. Finally, don’t be surprised if you have to wait until after 17.00 in the afternoon to get decent photos with no sunlight interference – although some of our Gabon plots are on the equator, which may explain this 

The intensive carbon cycling plots data collection campaigns in Amazonia, Africa and South East Asia continue to run smoothly thanks to the hard work and dedication of the GEM field teams. Also, the Peruvian teams have embarked on a massive leaf traits collection effort lead by Drs. Norma Salinas, Lisa Bentley and Allie Shenkin with the support of an excellent and hard-working Peruvian field team. We will provide a report on this new project in a couple of months.

Please continue sending your news and questions from the field, your colleagues from around the world are keen to hear about your experiences on the same work from another continent! All your news and photos are very welcome.

Over the summer we have received funding to set up new GEM plots in Brazil along disturbance gradients, in Malaysia, and to conduct traits and ecophysiology studies in Brazil, Malaysia and Ghana.

In June, the Association For Tropical Biology celebrated its 50 year anniversary in Costa Rica. Yadvinder was a speaker and gave a talk presenting new GEM results from Amazonia: http://atbc2013.org/

In August, the Andes Biodiversity Ecosystems Research Group (ABERG) had their 10 year anniversary meeting. It was a vibrant week during which all the researchers working on the transect had the opportunity to present their work. Amongst these, the Peruvian GEM teams presented an astonishing array of studies on plant traits (CHAMBASA project) and carbon dynamics being carried out along the transect. With a maximum elevation of 3600 m (the GEM plots at Acjanaco), the Kosnipata transect is now the longest and possibly the most thoroughly studied elevation transect in the world. We have a Dropbox with all the presentations from the conference. If you would like access to it, please respond to this post and I will get you access. Justin Catanoso, a US journalist who accompanied Profs. Miles Silman and Ken Feeley on their field trip and joined the ABERG meeting reported on it in these articles: